In a dual push-push type switch device, as is well known in the art, a pair of lock pins are provided on the sides of the bases in correspondence to heart-shaped cam parts provided respectively for a pair of operating pieces. In operation, whenever each operating piece is pushed the respective cam part is engaged with the lock pin to hold the operating piece at the push position thereof. Upon release of the engagement the operating piece is returned to its original position. These operations are repeated alternately.
In addition, a movable operating member is provided between the pair of lock pins in such a manner that, when one of the operating pieces is pushed with the other operating piece held at its push position, the operating member is moved by the lock pin provided for the is forcibly disengaged to return the other operating piece to its original position.
When, in the switch device thus constructed, the pair of operating pieces held at the original positions are pushed simultaneously, the top end portions of the lock pins tend to move along the cam grooves provided around the cam protrusions of the cam parts while abutting against the cam protrusions. In this way, the operating member between the lock pins is held in balance as it is pushed by the top end portions. If, under this condition, the two operating pieces are further pushed, since the lock pins have no relief space, the additional pushing force may damage the cam protrusions which are abutted against the top end portions of the lock pins, or deform the top end portions of the lock pins. This difficulty is liable to occur as the switch device is miniaturized.